Autochthonous Sheep Breeds Research Articles

Looking for added value of milk products of autochthonous sheep breeds

In order to determine the added value of the product, characterization of sheep milk and cheese samples from Sjenica sheep were assessed and compared to British milk sheep. The analyses were carried out according to standard chemical procedures. A comparative study showed that the milk from the Sjenica sheep was higher in fat and protein and had a lower casein/fat ratio. It also had higher total and somatic cell counts than British milk sheep. Sjenica cheese had significantly higher dry matter and fat content. However, both cheeses were classified as soft full-fat cheese with brine. The study showed that sheep's milk contains many essential components for cheesemaking and distinguishes sheep's cheese from other types of cheese, but standardisation of cheese production is still needed. To preserve the autochthonous sheep breeds of Serbia, promoting cheese production with added value is crucial and together with increased production could contribute to the sustainable development of rural areas.

New Strategies for Conservation of Gentile di Puglia Sheep Breed, an Autochthonous Capital of Millennial Tradition in Southern Italy.

Gentile di Puglia (GdP) is an autochthonous sheep breed of Southern Italy included among ovine breeds threatened by genetic erosion and extinction risk, which have been given attention by local and international institutions, thus emphasizing the need for germplasm conservation actions. In the present study, two assisted reproduction approaches, finalized for GdP conservation, were performed: (1) on-farm reproductive efficiency evaluation, expressed as pregnancy rate (PR), twin pregnancy rate (tPR), and body condition score (BCS), for three consecutive breeding cycles and (2) pre-pubertal lambs' immature cumulus-oocyte complex (COC) retrieval, vitrification, in vitro maturation (IVM), and assessment of meiotic stage and bioenergetic-oxidative status compared with those of other Italian and European commercial breeds. PR and tPR were progressively reduced over time. In all clinical examination times, BCS was significantly lower in nonpregnant ewes compared with pregnant ones. Fresh GdP pre-pubertal lamb COCs achieved meiotic maturation and showed healthy bioenergetic-oxidative status after IVM. Vitrification reduced the oocyte maturation rate in all groups. However, mature oocytes retained their cytoplasmic maturity, expressed as a mitochondria distribution pattern and activity, indicating promising developmental competence. In conclusion, clinical- and biotechnological-assisted reproduction approaches can support conservation strategies of GdP and other local sheep breeds in Southern Italy.

A study on the genetic diversity and subpopulation structure of three Bulgarian mountainous sheep breeds, based on genotyping of microsatellite markers

Traditional domestic breeds of domestic animals are part of the “living” wealth of the world, part of the disappearing biodiversity and a valuable local gene pool. Nowadays, they are increasingly included in the category of “rare and disappearing” breeds. Therefore, the purpose of this study was to reveal the genetic diversity and population structure of three Bulgarian mountainous sheep breeds (Rhodopean Tsigai, RT; Middle Rhodopean sheep, MRS; and Karakachan sheep, KS). A total of 113 unrelated individuals (two flocks of each breed) from different regions of the country were investigated based on 11 STR (short tandem repeat) markers. The obtained results showed a total of 116 alleles in the three sheep breeds. The mean number of alleles, effective number of alleles, and polymorphism information content (PIC) values per loci were 8.21, 4.72, and 0.79. The largest number of alleles were found in the population of MRS (9.18 ± 0.76), followed by RT (8.27 ± 0.64) and KS (7.18 ± 0.47). The largest polymorphism was found in INRA005 and INRA06 loci with 11 and 10 alleles, respectively, and the smallest polymorphic loci were noted for the locus McM042 and INRA172 with only 6 alleles. The observed heterozygosity showed the highest value in KS (0.79 ± 0.04), followed by RT (0.76 ± 0.02) and MRS (0.73 ± 0.04). The range of expected heterozygosity was from 0.77 ± 0.02 in MRS to 0.75 ± 0.03 in KS. The fixation index FST, estimated by analysis of molecular variance (AMOVA), was 0.2090, indicating moderate levels of genetic differentiation among the populations. The FST between the investigated breeds indicated a moderate value of 0.216, and the analysis of variance (ANOVA) data showed only 1% variation among the populations, whereas 99% was due to variation within breeds. The results by the STRUCTURE analysis revealed that all breeds were heterogeneous and formed three distinct clusters. The results of the genetic diversity and structure analysis of the investigated breeds provide useful information for assessing the genetic diversity of other Bulgarian autochthonous sheep breeds, serving as a cornerstone for designing effective conservation management strategies.

Genetic Diversity and Population Structure of Bulgarian Autochthonous Sheep Breeds Revealed by Microsatellite Analysis.

This study attempts to provide a deeper insight into the current genetic status of 12 Bulgarian autochthonous sheep breeds using microsatellite (SSR) markers. A total of 600 individuals from 50 flocks were analyzed using a panel of 13 SSR markers. In total, 228 alleles were found in the studied microsatellite loci. The mean number of alleles, the effective number of alleles, and the polymorphic information content (PIC) values per locus were 17.54, 5.250, and 0.799, respectively. The expected heterozygosity (He) for all breeds ranged from 0.70 to 0.82. The within-population heterozygote deficit (Fis) varied from -0.03 to 0.1, reflecting significant levels for 10 of the 12 breeds. The average genetic differentiation (Fst) was 0.046, revealing a low discrimination between the breeds. The genetic distance, principal coordinate analysis, and the structure analysis showed that two of the studied breeds-Local Stara Zagora/SZ/ and Local Karnobat/MK/-were the most distinct sheep populations. The Bayesian clustering approach suggested poor breed differentiation for the remaining 10 sheep breeds. The results suggest that proper management strategies and specific breeding policies need to be implemented in Bulgaria to avoid the intermixing of breeds and to reduce the erosion of breed purity observed in some breeds.

Genetic Diversity and Trends of Ancestral and New Inbreeding in German Sheep Breeds by Pedigree Data.

In Germany, many autochthonous sheep breeds have developed, adapted to mountain, heath, moorland, or other marginal sites, but breeds imported from other countries have also contributed to the domestic breeds, particularly improving wool and meat quality. Selective breeding and the intense use of rams may risk losing genetic diversity and increasing rates of inbreeding. On the other hand, breeds with a low number of founder animals and only regional popularity may not leave their endangered status, as the number of breeders interested in the breed is limited. The objective of the present study was to determine demographic measures of genetic diversity and recent as well as ancestral trends of inbreeding in all autochthonous German sheep breeds and sheep of all breeding directions, including wool, meat, and milk. We used pedigree data from 1,435,562 sheep of 35 different breeds and a reference population of 981,093 sheep, born from 2010 to 2020. The mean number of equivalent generations, founders, effective founders, effective ancestors, and effective founder genomes were 5.77, 1669, 123.2, 63.5, and 33.0, respectively. Genetic drift accounted for 69% of the loss of genetic diversity, while loss due to unequal founder contributions was 31%. The mean inbreeding coefficient, individual rate of inbreeding (∆Fi), and realized effective population size across breeds were 0.031, 0.0074, and 91.4, respectively, with a significantly decreasing trend in ∆Fi in 11/35 breeds. New inbreeding, according to Kalinowski, contributed to 71.8% of individual inbreeding, but ancestral inbreeding coefficients showed an increasing trend in all breeds. In conclusion, in our study, all but one of the mountain-stone sheep breeds and the country sheep breed Wald were the most vulnerable populations, with Ne < 50. The next most endangered breeds are exotic, country, and heath breeds, with average Ne of 66, 83, and 89, respectively. The wool, meat, and milk breeds showed the highest genetic diversity, with average Ne of 158, 120, and 111, respectively. The results of our study should help strengthen conservation program efforts for the most endangered sheep breeds and maintain a high genetic diversity in all sheep breeds.

A Search for Eurasian Sheep Relationships: Genomic Assessment of the Autochthonous Sheep Breeds in Russia and the Persian Plateau

Genomic assessment of local sheep breeds is relevant to the reconstruction of post-domestication migrations and to filling in gaps in the developmental history and contemporary phylogeographic-differentiation patterns in Eurasia. In this study, we aimed to reveal possible genetic relationships between local sheep breeds in Russia and the Persian Highlands (Iran) based on high-density SNP genotypes. All samples (n = 395) from 11 Iranian and 10 Russian sheep breeds were genotyped by using the Ovine Infinium HD BeadChip (Illumina, San Diego, CA, USA). Principal Component Analysis, maximum-likelihood assessment, and Neighbor-Net graph analysis demonstrated a clear differentiation between Russian sheep breeds of European ancestry from the Iranian local cluster and Russian breeds of Asian origin. Admixture analysis revealed a shared ancestral background, which was detected in several Iranian-local and Russian-local fat-tailed coarse-wool sheep breeds. Our findings contribute to a better understanding of the pattern of historic admixture, which is present in the genomes of many Eurasian sheep breeds.

Evaluation of Maternal Genetic Background of Two Hungarian Autochthonous Sheep Breeds Coming from Different Geographical Directions.

Simple SummaryBy the 19th century, adequately producing, independent domestic animal breeds had developed in many regions around the globe. However, from the middle of the 20th century they have largely been replaced by high-performing, specialized, single-purpose cosmopolitan breeds. Breed maintenance is an activity aimed at rescuing old breeds from the threat of extinction. This process includes recording the valuable traits of a rare breed, specific diversity conservation selection, and utilization in the original production environment. Additionally, it deals with the history of breeds and the study of their genetic makeup. The aim of this paper is to evaluate the maternal genetic background of two autochthonous sheep breeds in Hungary.The aim of our research was the evaluation of the maternal genetic background of two Hungarian autochthonous sheep breeds of different geographical origin. A major argument for the preservation of endangered animal breeds is their documented past and historical importance. These also include the registration of pedigree data. This is the first study to evaluate and compare Tsigai and Cikta sheep in Hungary. Our investigation is based on two complete sequences of mitochondrial DNA (cytochrome b gene and control region). Our research was performed on these two sheep breeds with markedly different breed histories and breed characteristics to determine a possible common maternal genetic background, as ultimately the origin of both breeds can be traced back to Asia Minor. Between 2015 and 2017, a total of 203 biological samples were taken using a newly introduced founder sampling method. We found that the prevailing haplogroup B accounted for over 80% of both breeds, strengthening the common ancestral root. However, the pairwise genetic differentiation estimates (KST) calculated using the sequence-based statistics for cytochrome b gene and control region were 0.034 and 0.021, respectively (both at level p < 0.05); thus, revealing genetic differentiation in both sequences between the Tsigai and Cikta. We note that the known different history of the breeds is clearly justified by the currently studied deviations in their maternal genetic background.

Lamb Meat Quality and Carcass Evaluation of Five Autochthonous Sheep Breeds: Towards Biodiversity Protection.

Simple SummaryThe biodiversity protection represents a challenge of the agenda ONU 2030 for Sustainable Development Goals (SDG). Autochthonous sheep breeds, including Altamurana, Bagnolese, Gentile di Puglia, Laticauda and Leccese, reared in continental Southern Italy, are strongly affected by extinction risk; thus, it is urgent to find new solutions to valorise their products and obtain sustainable and smart food from local farms. The objective of the present study was to assess the lamb carcass commercial quality, chemical and fatty acid composition of Altamurana, Bagnolese, Gentile di Puglia, Laticauda and Leccese autochtonous sheep breeds. Data on EU Mediterranean classification showed that the carcasses from both Bagnolese and Laticauda breeds were classified in the heaviest category C. Moreover, breed can influence the meat fatty acids profile, which is resulted rich in conjugated linoleic acid with good nutritional properties; thus, lambs’ meat from autochthonous sheep breeds can be considered interesting for human consumption. The present study can help to protect the biodiversity of livestock heritage of Southern Italy and open a new field for the valorisation and promotion of their derived products.In the present study, the evaluation of the carcasses and meat quality, in terms of chemical composition and fatty acid profile, of lambs from five autochthonous sheep breeds (Altamurana, Bagnolese, Gentile di Puglia, Laticauda, and Leccese) reared in continental Southern Italy, were studied. All the carcasses were evaluated according to the EU Mediterranean classification system for carcasses weighing less than 13 kg. Meat chemical composition and fatty acids profile were assessed on both loin and leg commercial cuts. Fatty acid composition of loin resulted in differences among breeds, displaying lower values of saturated fatty acid in Altamurana, Bagnolese, and Leccese breeds and the highest content of polyunsaturated fatty acid in the Altamurana breed. Principal component analysis grouped lamb according to fatty acid content and to conjugated linoleic acid (CLA), omega n-3 and n-6 fatty acids; thus, Altamurana, Bagnolese, and Leccese breeds are characterized by the highest values of CLA content. Our data demonstrated that lamb meat from autochthonous breed has good carcass quality and the content of CLA, n-3, and n-6 was valuable for human consumption; therefore, the valorisation of local meat quality can help to avoid the extinction of the autochthonous breed offering to the market and consumer’s high nutritive products.

A 2-Year Longitudinal Seroepidemiological Evaluation of Toxoplasma gondii Antibodies in a Cohort of Autochthonous Sheep from Central Portugal.

(1) Background: Toxoplasma gondii is an important zoonosis and one of the major causes of abortion in sheep worldwide. (2) Methods: We performed a 2-year longitudinal serological anti-T. gondii IgG screening on a cohort of a spatially confined population of a Portuguese autochthonous sheep breed in central Portugal. (3) Results: From the screening of the 2015 and 2016 sera, an increase of seroprevalence was observed (57.7% (95% CI: 49.9–65.3%) versus 69.1% (95% CI: 61.5–75.9), from 2015 and 2016, respectively) (p = 0.031). (4) Conclusions The present study is the first to provide prospective data on the anti-T. gondii serological status of a sheep cohort in Portugal, showing an increase in the occurrence of T. gondii. There is a need to provide a clearer understanding of T. gondii epidemiology in Portugal, ideally by implementing monitoring programs on sentinel herds, not only due to the high impact of T. gondii on animal health but also for it being a zoonosis.

Performance, carcass conformation and meat quality of suckling, weaned and heavy lambs, and culled fattened ewes of autochthonous alpine sheep breeds

Several local sheep breeds of the Alpine regions are in danger of extinction as a result of mountain farms being abandoned. Three fattening trials were carried out on 4 breeds of the Veneto region (Foza, Lamon, Alpagota, and Brogna) on a total of 115 ewes and suckling lambs, weaned lambs and heavy lambs slaughtered at 1356 ± 267, 104 ± 24, 219 ± 26, and 342 ± 14 d of age, respectively. The results confirmed that the adoption of total mixed diets resulted in good in vivo and post mortem performances of culled ewes (64 kg slaughter weight, 48% dressing percentage), suckling lambs (21 kg, 50%), weaned lambs (30 kg, 42%) and heavy lambs (61 kg, 48%). Carcass compactness and fatness increased with the age of the lambs, whereas the proportions of lean meat and bone decreased. Meat lightness and cooking losses decreased with age, whereas redness and chroma increased. The meat quality of culled ewes was like that of heavy lambs. Carcass conformation and composition (aside from size traits), and the quality of the meat differed little among the four Alpine breeds. These results show that local breeds are potentially valuable sources of lamb and mutton meat across different seasons, paving the way for strategies to develop and promote the meat with the involvement of high-quality restaurants and meat retailers. Highlights Compared to outdoor grazing, the adoption of indoor diets resulted in good in vivo and post-mortem performances of ewes, suckling lambs and heavy lambs. Autochthonous Alpine breeds are potentially valuable sources of high-quality lamb and mutton across different seasons of the year. This potential could be exploited in developing a prestigious product aimed at high quality restaurants and butchers. The subsequent demand for the product would, in turn, contribute to the survival of the local sheep breeds of Alpine regions.

Effects of feeding system and CLA supplementation on animal, carcase and meat characteristics of fattened lambs and ewes

To promote local food products could be a valuable strategy for preserving autochthonous sheep breeds. A total of 115 lambs and ewes of local sheep breeds (Alpagota, Bogna, Foza and Lamon) of the Veneto region were used to evaluate the effect of different feeding systems on the production and quality of lambs and mutton meat. We carried out three fattening trials involving 24 ewes and their 31 suckling lambs, 24 weaned lambs, and 24 heavy lambs, fed indoor diets with or without a rumen-protected conjugated linoleic acids (rp-CLA) supplement (C18:2c9,t11 and C18:2t10,c12) to improve the nutritional value of the meat. Controls were a group of 12 pasture-fed weaned lambs. The weaned lambs at pasture had good fattening performances (33 kg live-weight at slaughter, 45% dressing percentage), whereas lambs fattened indoors on hay and some concentrates had lower weight (28 kg) and dressing percentages (41%), and require improvements to their feed. Feeding the animals on total mixed diets resulted in good in vivo and post mortem performances of culled ewes (64 kg slaughter weight, 48% dressing percentage), suckling lambs (21 kg, 50%) and heavy lambs (61 kg, 48%), showing that valuable supplies of lamb and mutton meat can be obtained across different seasons. Supplementing indoor diets with rp-CLA does not modify the animals’ performances nor the organoleptic traits of meat. Highlights Intensive indoor fattening allows to obtain suckling, weaned and heavy lambs and mutton from culled ewes all-year-round beyond the seasonal supplies of traditional feeding system. The supplementation of indoor diets with rp-CLA does not modify the animals’ performances, slaughter traits or meat organoleptic traits.

Assessment of the genetic diversity of Two Czech autochthonous sheep breeds

Based on pedigree information, the population structure, within-breed genetic variability and causes of genetic variability losses in Wallachian sheep (WS), and Sumava sheep (SS) were studied. The maximum number of generations observed in both WS and SS was 16, and the equivalent number of complete generations 5.66 and 4.35, respectively. The average generation intervals were in WS and SS 4.33 and 4.72 years, respectively. A span of four years, 2015–2018, was used as the reference population (animals from the last generation). The average inbreeding coefficient and average relatedness coefficient were 5 % and 9 % for WS, while both were 3 % for SS. The rate of the inbreeding coefficient was 0.5 % in WS and 1 % in SS. The effective number of founders, effective number of ancestors and effective number of founder genomes were 104, 50 and 22.8 for SS and 39, 21 and 10.28 for WS. The effective population size based on an increase in the inbreeding coefficient and computed based on average coancestry were 50.61 and 64.5 in WS and 99.56 and 166.14 in SS. These results indicate a low value of genetic diversity in Wallachian sheep. The loss of variability was caused by the bottleneck effect and partly also genetic drift and the unequal contribution of the founders.

Effect of genotype on adipose tissue fatty acids profile of two autochthonous sheep breed

Effect of genotype on adipose tissue fatty acids profile of two autochthonous sheep breed

Genetic variability following selection for scrapie resistance in six autochthonous sheep breeds in the province of Bolzano (northern Italy).

Scrapie is an ovine transmissible spongiform encephalopathy, and its susceptibility is associated with polymorphisms in the prion protein gene (PRNP). Genetic selection is currently the most effective mean for eradication of the susceptible VRQ allele in favour of resistant ARR allele. Maintenance of genetic diversity should be one of the major objectives in breeding programmes, especially in endangered breeds, and genetic information are an excellent alternative to pedigree data where these information are missing. The aim of our study was to determine changes of genetic variability in six native sheep breeds from autonomous province of Bolzano, northern Italy, following simulation of scrapie selection scenarios. A total of 684 rams were investigated for PRNP polymorphisms and for 10 microsatellite loci to estimate genetic variability. Across all loci, a total of 163 alleles were detected with a mean of 10.4 alleles per locus. Average observed (Ho) and unbiased expected (uHe) heterozygosity overall loci were 0.74 and 0.78, respectively, showing a statistically significant deviation from Hardy-Weinberg equilibrium (HWE) in all breeds. This heterozygosity deficit was confirmed by a positive fixation index (Fis), determining a moderate inbreeding in each breed. Simulating a soft selection, where only rams having at least a VRQ allele should be excluded from reproduction, Ho, uHe and Fis values remained almost unchanged, indicating that genetic variability should not be affected by the removal of these individuals. With a mild selection scenario, considering only rams with at least one ARR allele, we observed a decrease in the mean alleles per breed (8.9) and the maintenance of heterozygosity deficiency, except for two breeds, where it was any longer significant. These results showed that selection strategies allowing use of heterozygous as well homozygous ARR rams might be the right compromise to improve resistance to scrapie and to do not dramatically affect genetic variability of these breeds.

CHARACTERISTICS OF AUTOCHTHONOUS BREEDS OF RUSSIA AND KAZAKHSTAN BY MICRONUCLEAR TEST

The article is devoted to the results of the micronucleus test in two well-known autochthonous sheep breeds of the Russian Federation and the Republic of Kazakhstan: Romanov and Edilbay. In Romanov sheep, the highest rates of micronucleus occurrence were found in lambs (8.7 ± 0.9 ‰), than in producing rams (5.6 ± 0.03 ‰) and ewes (4.8 ± 0.3 ‰). The Edilbay breed has the differences in micronucleus test results in erythrocytes are most pronounced between two intrabreed types: “Birlik” and “Suyunduk”. The breeding plant “Birlik” is located in the Ural, the West Kazakhstan region. “Suyunduk” type of Edilbay breed sheep are raised in the breeding plant “Makash” in the Atyrauz region of the Republic of Kazakhstan, located near the Azgir nuclear test site. The difference in the micronucleus test is due to the fact that sheep of the “Suyunduk” type are exposed to environmental stress factors due to the proximity of places with high levels of radionuclide contamination. The constant action of natural selection contributes to the reproduction of animals with increased resistance to environmental stress factors. This explains the low occurrence of cells with cytogenetic abnormalities in sheep of the “Suyunduk” Edilbay breed sheep type. This type has a higher potential for adaptation to adverse breeding conditions than the Birlik type of Edilbay breed sheep. The high level of micronucleus test indicators in sheep of the Romanov breed is associated with the peculiarities of gender and age groups, and also the environmental stress of climatic conditions in Central Russia. A classification of micronucleus is proposed. It is believed that large and medium-sized micronucleus are formed by the action of various mutagens on the body, causing a large in the division of individual chromosomes in metaphase and anaphase. Small micronucleuses indicate a decrease in potential cell viability.

A study on morphology and morphometric parameters on skull of the Bardhoka autochthonous sheep breed in Kosovo.

In this study, we aim to investigate the skull of Bardhoka sheep, which is the native breed of Kosovo by utilising normal morphometric methods. Differences between male and female were also statistically analysed. Further, the parameters that can be used in gender discrimination were also analysed. The statistical analysis was based on a sample of 24 adult skulls of Bardhoka breed with 12 female and 12 male skulls. Altogether, 31 different measurements were taken morphologically and 7 different indices were applied. Except for the measurement's values of the orbit, measurement's values of length of the cheek tooth row and the measurement's values of height of the foramen magnum, all the measured values of males were higher than females. Nasal index, cranium index and skull index values were statistically significant between both genders. It is envisaged that the findings of this study will motivate and assist other comparative studies with other autochthonous sheep and goat breeds found in the Dukagjini region or in clinical veterinary practice and even in zooarchaeology.

Productivity of Krivovir Strain and its Importance on Sheep Farming in Republic of Serbia

The area of central Serbia is very suitable for sheep production, because of it’s hilly and mountainous configuration. Such area is rich in pastures for ruminants. In the territory of central Serbia, representative of autochthonous (indigenous) sheep breeds is pramenka (zackel) with its differentiated strains: Sjenica strain, Svrljig strain, Krivovir strain, Karakachan strain, Pirot strain, Lipa strain and Bardoka (White Metohian strain). Aim of this study was to investigate Krivovir strain: number of controlled heads and their part in total sheep population, their productivity parameters and milk parameters. In this study, total of 789 adult animals were observed. Average observed body weight (BW) of lambs were: BW on birth 3.22 kg, BW after 30 days 10.55 kg and BW on weaning 24.99 kg, while BW of adult sheep was 50.52 kg. Fertility index was 1.17 and average wool production was 2.88 kg. Average lactation after weaning lasted for 100 days, with milk production 65.16 kg, 3.91% protein and 6.72% milk fat. Krivovir strain is participating with 0.4% of total number of controlled sheep in central Serbia. Although in small number, this strain is irreplaceable in sustainable systems because they are evolutionary adapted to the conditions in which they are reared and because of their contribution to gene pool and agro-biodiversity.

Gastrointestinal parasites as a possible threat to an endangered autochthonous Portuguese sheep breed

Helminth and protozoan infections are responsible for important diseases in grazing sheep, which can be especially threatening in an autochthonous breed at risk of extinction like the Churra Galega Mirandesa Portuguese sheep breed. The aim of the present study was to determine the diversity, prevalence and burden of gastrointestinal parasites in these sheep and to assess the effects of deworming practices, cohabiting animals on the farm and feed management. Coprological qualitative and quantitative analysis (flotation, natural sedimentation and McMaster method) were used to identify and quantify gastrointestinal parasites and a questionnaire was designed and applied. A total of 512 faecal samples were collected from 49 flocks, and 49 replies to the questionnaire were received. Parasites were identified in 100% of the flocks, and in 97% of the samples. The genera or species that have been morphologically identified were: strongyle-type, Nematodirus spp., Skrjabinema spp., Moniezia expansa, Moniezia benedeni, Trichuris spp., Capillaria spp., Eimeria spp., Dicrocoelium spp. and Fasciola hepatica. This is the first report in Portugal of Skrjabinema spp. The burden of parasites' oocysts and eggs per gram in faecal samples ranged, respectively, from 50 to 17,550 for Eimeria spp., and from 50 to 6250 for strongyle-type eggs. Factors affecting parasitic infections were evaluated using a multivariate logistic regression. Grazing time and a lack of anthelmintic treatment were positively associated with Nematodirus spp. infection. This study showed that there is a high prevalence and diversity of gastrointestinal parasites in the Churra Galega Mirandesa sheep breed.

Genetic variation of Bulgarian autochthonous sheep breeds using microsatellite markers

The aim of the study is focused on the design of a conservation sheep breeding programme for the studied autochthonous breeds based on SSR markers genetic variation analysis applied. Seven local Bulgarian autochthonous sheep breeds (Breznishka, Sofiiska, Copper-Red Shumenska, Karakachanska, Local Karnobatska, Blackhead Plevenska and Starozagorska) were differentiated using six microsatellite (SSR) markers, aiming to assess the genetic variation within and between breeds. Among the total of 96 identified alleles, eighteen population specific ones were detected across the all studied genotypes of 338 individuals, except in the Blackhead Plevenska sheep. All examined breeds indicated high level of genetic diversity, with an average of 0.792. The genetic differentiation between the examined sheep breeds was not significant and the values of genetic distances were relatively low. The analysis of molecular variances (AMOVA) showed low variation between the examined breeds (5.51%) in comparison to within population variation (94.49%). The greatest distance (0.643) was found between the populations Local Karnobatska and Starozagorska, while the smallest one (0.108), between the Copper-Red Shumenska and Karakachanska. The genetic distances calculated by Neighbour-Joining method, produced a phylogenetic tree which separates the investigated sheep breeds into two main clusters: one including Blackhead Plevenska Breznishka and Local Karnobatska, and the other one consisting of the four remaining breeds - Copper-Red Shumenska, Karakachanska, Sofiiska and Starozagorska sheep. The Factorial Correspondence Analysis (FCA) showed isolation of Local Karnobatska sheep and Starozagorska and an admixture of the other populations.

Genetic Differentiation and Similarity Degree Quantified by Statistical Parameters in the Romanian Sheep Breeds

The paper proposes some procedures for quantifying the biological relations among the four main indigenous sheep breed types from Romanian (Merino, Tsigai, Tsurcana and Karakul) depending on their genetic endowment. The investigational support of these interrelations was represented by the allelic configuration within the five biochemical-genetic systems (haemoglobin, transferrin, albumin, amylase and blood potassium), six immunogenetic systems (A, B, C, D, M and R-O) and two molecular-genetic systems (β-lactoglobulin and calpastatin). The measurability of these interrelations is feasible by means of a mathematical (classical) parameter - the genetic distance (D) – which estimates the genetic differentiation degree among the breeds and an informational statistics concept - the informational correlation (Cx,y) - which reveals the genetic similarity degree among these taxonomic entities by calculating the informational correlation coefficient (Rx,y). At the same time, the paper tries to discriminate which of these two statistical indicators is more eloquent to characterize the biological relations among these sheep breeds. On the basis of values of these statistical parameters, the genetic similarity or differentiation degree among the autochthonous sheep breeds from Romania has been interpreted also by numerical classification methods of biological systems: cluster analysis (CA), multidimensional scaling (MDS) and discriminatory analysis (DA). The paper describes the usefulness of these statistical parameters in the selection, improvement and breeding field in the ovine species.